Railway-traffic-controlling apparatus



March 20, 1928.

' v A. A. SKENE ET AL RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Dec.20 1926 & gslwu fi m m VH. 6 a m w W Q E E 6% QM ww MN \N v V QM mWN mmmm mm .rmm T k mm H k N NE W Q. B WMN All W HA. T P

Patented Mar. 20, 1928.

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ANDREW A; SKENE, or wiLKrnsBURe, AND HOWARD A. rnomrson, or mambo]:

BOROUGH, PENNSYLVANIA, ASSIGNORS To THE UNION swIiiici-I & siGivA-L001i:-

r NY; or swrssvana, rann'sYLvr-inrii, e con-rci'aarion or rEnitsrLvANrA;

RAILWAY-TRAFFIC-CONTROLLING APPARATUS.

Application filed December 20, 1926. Serial No. 155,844.

Our invention relates to railway trafiic controlling apparatus, andparticularly to apparatus of the type comprising train carried governingmeans controlled by energy received from the trackway.

lVe will describe one form of railway traflic controlling apparatusembodying our invention, and will then point out the novel featuresthereof in claims.

The accompanying drawing is a diagrammatic view illustrating one form ofrailway traflic controlling apparatus embodying our invention.

Referring to the drawing, the reference characters 1 and 1 designate thetrack rails of a stretch of railway track over which trafiic normallymoves in the direction indicated by the arrow. These rails are divided,by means of insulated joints 2, into a plurality of successive tracksections, only one of which, A-B, is shown in the drawing.

Each track section is provided with a track relay designated by thereference character It with an exponent corresponding to the location,and connected across the rails adjacent the entrance end of the section.Associated with relay R is a repeater relay P which is connected withterminals X and Yof a suitable source of energy, not shown in thedrawing, over front contactt9 of relay R Relay P is therefore energizedonly when relay R is energized.

A track transformer T has its secondary 7 constantly connected acrossthe rails adjacent the exit end of section AB through the usualimpedance 9. Section A-B is therefore provided with a track circuitcomprising the secondary 7 of transformer T, impedance 9, relay R andthe rails of thesection in series. The section is also pro vided with aloop circuit over which current is supplied to the railsof the sectionin par allel. For this purpose two impedances 12 and 18 are connectedacross the rails adjacent the entrance end and the exit end, re-

spectively, of the section, and secondary 10 of a loop transformer L isconnected with the mid-point of these impedances.

Alternating currents are supplied to the trackway through a plurality oftransformers G, D and 7E. The primary oftrans-V former C is suppliedwith alternatingi'current of onefrequency from an alternator F,

through a transformer C over line wires 3 and 4t Transformer is suppliedwith alternating'current through a transformer D from an alternator G,over line wires 5 and 6. A third alternator H supplies alternatingcurrent to the primary of a transformer E the secondaryof which isconnected with the mid-points of the secondaries of transformers C and DTransformer E has its primary connected from the mid-point of theprimary of transformer C to the mid-point of the primary of transformerD. It will therefore be plain that the primary of transformer E issupplied with alternating current from transformer E over a phantomcircuit through wires 3-, 4, 5 and 6. The alternators F, G and arearranged to supply alternating currents, of

slightly different frequencies. These fre-.

quencies may have any suitable values, but

for purposes of explanation we will assume that alternator F vdeliverscurrent of -cycles per second, that' alternator G delivers current of.59 cycles per second, and that alternator H delivers current of58cycles per second. In order to maintain constant the relative valuesof the frequencies of the currents delivered by the three alternators F,

,G and H, we preferably connect the alternators mechanically.

When section AB is unoccupied, so

that relay R? and relay Pare energized,

current is supplied from transformer C to the primary 8 of transformer Tover a cir cuit which passes from the secondary of transformer 6,through wire 14L, front co n- ,t-act 15 of relay P, wires 16 and17,,primary lay R is energiz'edwhen relay P is'deenergized, currentflows from the secondary of transformerE, through wire 23,, frontcontact 24: of relay R wire 25, back contact 26 of'relay P, wires27"and17, primary 8 of transformer' T and wires 18', 1 9, 28; and

29, back to the secondary oftransforiner roe If, however, relay B is'de-energized, as by the presence of a train in the section to the rightof point B, and if relay P is de-energized, current flows from thesecondary of transformer D, through. wire 30, back contact 24 of relay Rwire 25, back contact 26 of relay P, wires 27 and 17, primary 8 oftransformer T, and wires 18, 19 and 28, back primary of transformer Lfrom transformer C so that under these conditions the loop cir- V cuitof section A-B is supplied with 60- cycle current. At the san'ie timethe primary of transformer T is connected with transformer D or'withtransformer E, de-

pending upon the condition of relay R so that the track circuitforsection AB is supplied with alternating current of 59 cycles or 58cycles depending upon traflic conditions in advance. f

The reference character V designates a train which isprovided with tworeceivers K and K each comprisingtwo magnetizable cores 31 and 31carried in inductive relation with the two track rails 1 and 1respectively. Each of the cores 31 is provided with a winding 32 andeach of the cores 31 is provided with a similar winding 32 The receiverK is located in advance of the forward axle of the train and thewindings 32 and 32 of this receiver are connected in series in suchmanner that the voltages induced therein by current which flows inopposite direction in the two track rails at an instant are additiveThis receiver may therefore be called a track receiver because it isresponsive to alternating current supplied to the track circuit of thesection occupied by the train. The windings 32 and 32 of the receiver Kare connected in series in such manner that the voltages induced thereinby alternating currents which flow in'the same direction in the trackrails at an instant are additive. This receiver may therefore be calledthe loop receiver because it is responsive to loop current in the trackrails of the section occupied by the train. The track receiver K andtherloop receiver K are connected, through amplifiers of any suitabletype, with the windings 33 and 34,;respectively, of an induction motorrelay J. This relay'is provided with an armature 35 which swingsa-contact 36 in one direction or the other depending upon the relativepolarity of the alternating cur rents supplied to windings 33 and 34.

When the train V occupies a section which is supplied with loop currentand with track circuit current, it will be plain that currents ofcorresponding frequencies will be supplied to windings 34 and 33 ofrelay J. As a result the contact 36 will be swung in one direction eachtime the currents in windings 33 and 34 are in phase and will be swungin the opposite direction each time the currents in these windings are180 out of phase. It will be plain therefore that the frequency ofoscillation of the contact 36 of relay J will correspond to thedifference between the frequencies of the currents supplied to windings33 and 34. In other words, the frequency of oscillation of contact 36will be equal to the beat fre quency of the currents in the two windingsof the relay J. If the track circuit is being supplied with 58-cyclecurrent and the loop circuit is being supplied with 60-cycle current thebeat frequency will be two cycles per second and the frequency ofoscillation of relay J will also be two cycles per second. If, however,the track circuit is being supplied with 59-cycle current and the loopcircuit is being supplied with (SO-cycle current,

the beat frequency will be one cycle per sec- 0nd and relay J willoscillate once per sec- 0nd. V

The train may be provided with, decoding apparatus of any suitable typewhich is selectively responsive to the frequency of oscillation'of therelay J. As shown in the drawing this decoding apparatus is similar tothat shown and described in an application for Letters Patent of theUnited States, Serial No. 112,491, filed May '29, 1926, by Clarence S.Snavely,'for railway'traffic con trolling apparatus. This apparatuscomprises two transformers Q and S, the primaries 38 and 39 of which aresupplied with. periodically reversed direct current from a battery 37under the control of contact 36 of relay J. As shown in the drawing,when contact 36 swings to the left to close contact 3636 current flowsthrough the lefthand portions of primary 39 of transformer S and primary38 of transformer Q, in one direction, and when contact 36 swings to theright to close contact 3636", current from battery 37 flows in theopposite direction through the right-hand portions of primaries 38 and39. The secondary 41 of transformer S is connected through a rectifierwith a relay 43, and the secondary 40 ofthe transformer Q, is connectedthrough a rectifier with arelay 42. Itwill therefore be plain that. theflux in-the transformers Q, and S is periodically reversed at'thefrequency of oscillation of contact 36.

The parts are so proportioned that when relay J is operating one cycleper second iii) to reverse the flux in transformer Q once per second,the core of the transformer is substantially saturated and relay 42 issupplied with sufiicient energy to pick up the relay. It follows thatrelay 42 will also be energized when the flux is being reversedsaturation of the core, and since they are less rapid the energysupplied to relay 43 s not sufficient to energize the relay. The relays42 and 43 control governing means of any suitable type. In the form hereshown a proceed lamp 46 is supplied with energy from battery 37, overfront contact 45- 45 of relay 43, a caution lamp 47 is supplied withenergy from battery 37 over back contact 45-45 of relay 43 and frontcontact 44'44 of relay 42, and a stop lamp 48 is supplied with energyover back contact 4545 of relay 43 and back contact 4444 of relay 42.

We will now assume that'train V enters section A-B and that track relayR is energized. Relay R becomes tie-energized, thereby opening thecircuit for relay P and causing that relay to become tie-energized.60-cycle current is therefore supplied to the loop circuit and 58-cyclecurrent is supplied to the track circuit of section A-B. lVindings 34and 33 of relay J are thereforeenergized bycurrents of GO-cycles and(SS-cycles respectively, so that the beat frequency at whichthe'conta'ct 36 oscillates is two cycles per second. Under theseconditions, relays 42 and 43 are both energized so that the proceed lamp46 is lighted. If, however, relay R is de-energized, the loop circuit ofsection AB is supplied with (SO-cycle current as before, but the trackcircuit of this section is supplied with 59-cycle current so that thebeat frequency to which the relay J responds is equal to one cycle persecond. WVith relay J operating at this frequency, relay 43 istie-energized but relay 42 is energized so that the caution lamp 47 islighted. If the train enters an occupied section where it will bedeprived of "track circuit current or if it is deprived of loop currentor if for any other reason the relay J ceases to oscillate, relays 42and 43 will both be de-energized so that the lamp 48 will be lighted toindicate stop.

When the train leaves the section, the 59 cycle current supplied to thetrack circuit from transformer D, energizes relay R thereby closingrelay P and restoring the apparatus to its normal condition.

Although we have, in describing the apparatus embodying our invention,referred to a number of frequencies for the alternating currentssupplied to the trackway and for the beat frequencies to wliich therelay 5 is responsive it should be particularly pointed out that theseparticular frequencies are not essential, and have been specified simplyfor purposes of explanation. Furthermore, it should be noted thatalthough we have herein shown and described apparatus which suppliesonly two different frequencies to the track circuit we do not limitourselves to this number but that additional frequencies may be suppliedto the track circuit to operate relay J at an additional number offrequen- "cies to obtain upon the train an lncreased number ofindications.

Although we have herein shown and de 7 scribed only one form of railwaytraffic controlling apparatus embodying our invention, it is understoodthat various changes and modifications may be made therein within thescope of the appended claims without departing from the spirit and scopeof our invention. Having thus described our invention, what ,we claimis: I

1. Railway traffic controlling apparatus comprising means for supplyingthe trackway with two alternating currents of different frequencies, twotrain carried receivers separately responsive to such currents, a relayhaving two windings supplied with energy from the two receiversrespeetiv'ely,.

and governing means controlled by said relay in accordance with therelation between the frequencies of said currents.

2. In combination, a stretch of railway track, two traclrway circuitsforsaid stretch, meansfor supplying one circuit with alternating currentof a firstfrequency, means for supplying the other circuit withalternating currents of different frequencies, two train carriedreceivers separately responsive to the currents in said circuits, andgoverning means controlled by said receivers in accordance with thedifference between the frequencies of the currents supplied. to saidcircuits. I

3. Railway traffic controlling apparatus comprising means for supplyingthe trackway with two alternating currents of different frequencies, atrain carried-member arranged to oscillate at different frequenciesdepending upon the difference between the frequencies of said currents,and governing means on the train responsive to the frequency ofoscillation of said member. v

4. Railway traflic controlling apparatus comprising a train carriedrelay having two windings, means located in the trackway for Tilt) ill)causing alternating currents of different frequencies to flow in saidwindings, said relay having a movable member which is subjected to thevibromotive forces due to the joint action of such currents, andgoverning means selectively responsive to the frequency of oscillationof said member.

5. In combination, a stretch of railway track, two trackway circuits forsaid stretch, means for supplying one circuit with alternating currentof a first frequency, means for supplying the other circuit withalternating currents of different frequencies, and means on the trainselectively responsive to the difference between the frequencies of thecurrents in such circuits but not responsive to the current in eithersuch circuit alone.

6. In combination, a stretch of railway track provided with a loopcircuit and a track circuit, means for at times supplying alternatingcurrent of one frequency to the loop circuit, means forsupplyingalternating currents of different frequencies to the trackcircuit, and governing means on a train selectively responsive to the.difference between the frequencies of the currents in the loop and trackcircuits.

7. In combination, a stretch of railway track provided with a loopcircuit and a track circuit, means for normally supplying thetrackcircuit with alternating current of one frequency, means effective whena train occupies the stretch to supply alternating current of such onefrequency to the loop circuit, and to supply the track circuit withalternating currents of different frequencies depending upon trafficconditions, and governing means 011 the train selectively responsive tothe difference between the frequencies of the currents in such circuits;

8. In combinatioma forward and arear section of railway track, a trackrelay responsive to traffic conditions in the forward section, a tracktransformer having its secondary connected across the rails of the rearsection, a first impedance and a second impedance connected across therails adjacent the entrance end and the exit end, respectively of therear section, a loop transformer having its secondary connected withsuch impedances, two sources of alternating current ofdifferentfrequencies, means for at times connecting one said source with theprimary of the track transformer, andmeans'for at other times connectingsuch one source with a the primary of the loop transformer and forconnecting the remaining source with the primary of the tracktransformer.

9. Railway trafiic controlling apparatus comprising an induction motorrelay having ferent frequencies to such two windings, and v governingmeans controlled by the armature and responsive to the beat frequency ofsuch currents.

10. Railway traffic controlling apparatus comprising means for supplyingthe trackway with two alternating currents of different frequencies, amember arrangedto oscillate at the beatfrequency of such currents, andgoverning means responsive to the frequency of oscillation of suchmember.

11. In combination, a section of railway track, a loop circuit for suchsection, a track circuit for such section, means for supplying the loopcircuit with alternating current of a. single frequency, means forsupplying alternating currents of different frequencies to the trackcircuit, and governing means controlled jointly by the currents in theloop circuit and the track circuit.

12. In combination, a section of railway track, a loop circuit for suchsection, a track circuit for such section, means for supplying the loopcircuit with alternating current of a single frequency, means forsupplying alternating currents of different frequencies to the trackcircuit, and governing means responsive to the relation between thefrequencies of the currents in such circuits.

13. In combination, a section of railway track, a loop circuit for suchsection, a track circuit for such section, means for supplying the loopcircuit with alternating current of a single frequency, means forsupplying the track circuit with alternating currents of differentfrequencies in accordance with traffic conditions in advance, andgoverning means responsive to therelation between the frequencies of thecurrents in such circuits.

14. In combination, a section of railway track, a loop circuit for suchsection, a track circuit for such section, means responsive to trafficconditions in such section for supplying the loop circuit withalternating current of a single frequency, means for supplying the trackcircuit with alternating currents of different frequencies in accordancewith traffic conditions in advance of the section, and governing meansresponsive to the relation between the frequencies of the currents inthe loop and track circuits.

In testimony whereof we affix our signatures.

ANDREWV A. SKENE. HOWARD A. THOMPSON.

